Background The role of vitamin D in the etiopathogenesis of fibromyalgia and non-specific musculoskeletal pain is controversial.

Objectives In our study, we aimed to investigate the effect of vitamin D therapy on quality of life in patients with fibromyalgia.

Methods 70 patients diagnosed with fibromyalgia and 65 age-sex match controls were included in the study. Patients were grouped as deficiency (<20 ng/mL), inadequacy (20–30 ng/mL) and sufficient (>30 ng/mL) according to the levels of vitamin D. Vitamin D replacement was performed for patients with deficiencies and inadequacies. Before and after vitamin D therapy, patients filled in the assessment tools.

Results Vitamin D deficiencies and inadequacies were observed in 60% of the patients (n=42). Social function, mental health and vitality areas in patients' quality of life forms were significantly lower in normal vitamin D group compared with low vitamin D group. In scales examined after Vitamin D replacement therapy, statistically significant differences were observed in the fibromyalgia impact questionnaire, Beck depression inventory, VAS and SF-36 compared to pre-treatment.

Conclusions Since, vitamin D deficiency seems to be linked to the pathogenesis of FMS, serum vitamin D levels should be checked routinely as a general health problem and patients should be supplemented.

Disclosure of Interest None declared